Tube bender



Feb. 25, 1941. J. H. ABRAMSON ETAL 2,232,819

TUBE BENDER Filed July 22, 1937 3 Sheets-Sheet Feb. 25; 1941. J. H. ABRAMSON ETAL 2,232,819

TUBE BENDER Filed July 22, 1937 3 Sheets-Sheet 2 Patented Feb. 255-1941 UNITED STATES PATENT OFF-ICE ford,

11]., assignors to Greenlee Bros. & 00.,

Rockford, Ill.,.a corporation of Illinois Application July 22, 1937, Serial No. 154,982

4 Claims.

This invention relates to tube benders and has special reference to a bender adapted for hand operation, and in one aspectthereof particularly I adapted. for the bending of thin walled tubes and tubes of soft metal.

An object of the invention is the provision of a generally improved tube bending device.

Another object of the invention is the provision of a bender having a novel arrangement of bend ing segments and for-supplying members to provide a more useful and efiicient hand tool.

A still further object of the invention is the provision of a tube bending device having improved means for applying force to the tube during the bending" operations.

We have also aimed to provide a bending device wherein the walls ofthe tube'are subjected to a confining and compressive force while the metal is being distortedfi" A further object of ,the invention is the provision of a bending devicewherein the tube is simultaneously bent-and annularly confined and reduced in a progressive manner.

A still further object of the invention. is to pro- 25 vide a bending tool'having a shoe and followbar upon which the metal is bent, wherein the bending forces are applied solely by manipulation of the shoe and follow-bar.

An important object of the invention is the thin walled or soft metal tubes through curves of relatively short radius without flattening or rippling the tube.

Otherobjects and advantages will be apparent 35 from the following description and the accompanying drawings, in which Figure 1 is a side view of the bender showing the manner of its use;

Fig. 2 is an edgewise view of the body member and roller;

Fig.3 is a face view of the follow-bar;

Fig. 4 is a full sized side view' of the bender showing the parts in the position for starting a bend;

Fig. 5 is a view similar to Fig. 4 showing the relative positions of the parts at the end of the bending operation;

Fig. 6 is a section on the line 6-6 of Fig. 4

Fig. 7 is a section on the line '|-'l of Fig. 5, and

Fig. 8 is a section similar to Fig. 7 showing the roller moved for cooperation with the opposite segment to bend a pipe of smaller size.

The invention contemplates a tool or device for the bending of tubes which is particularly adapted for the bending of thin walled tubes or provision of a tube bending device for bending tubes made of soft metal such as copper without flattening or producing ripples in the tube due to the bending operations. In another aspect the invention contemplates a light weight tool adapted for manual manipulationsuch asmay 51 a be carried about by the workman from place to place and used directly on the job, the tool having a minimum of weight and a maximum of adaptability to different sizes of tubes.

Referring first to Figure l, the .bender includes a body member II, in this'instance of castmetal, having a segment orshoe l2 of relatively large radius, and a segment or shoe l3 diametrically opposed to the'segment l2, the segment l3 being of relatively small radius as shown 15 in the figure. The radii of the segments l2 and I3 corresponding to the radii of the bends to be formed in tubes of the prmcribed rangeas will presently become apparent, numerals being applied to the sides of the segments to designate the angularity. as shown in Figure l. The body a H is carried on a handle I4 having a threaded end I5 arranged for reception in either of two diametrically opposed threaded sockets l6 and I! on the edge of the body member. H.

Referring now more particularly to Figs. 6 and '7, the segment l2 has a pair of annulargrooves 12 and IQ of semi-circular cross-section, the diameter corresponding to the diameter of two standard sized tubes, while the segment l3 has a pair of grooves 2| and 22 of semi-circular crosssection which likewise corresponds to the diam- 1 eter of two. smaller standard sized tubes, the two shoes or segments thus permitting bending operations to be. performed on four sizes of tubes, in this particular instance, the tubes being of /2" and %"'outside diameter. Spaced from the leading end of segment I2 is an abutment member 23 having abutments 24 and 25 projecting laterally thereof in the planes of the grooves l8 and I9, the abutments havingarcuate surfaces 26 and 21 spaced radially from the arc of the segment l2, as best shown in Fig. 5, for the reception thereagainst of the side wall of tubes to be bent in thegrooves l8 and 19. An abutment member 28 likewise having abutments 29 and 3| provided with arcuate surfaces 32 and 33 is spaced beyond the leading end of the segment l3 and radially outward so as to receive pipes under the abutments in alignment with 'the grooves 2| and 22.

A shaft 34 extends through the body member H on the center of curvature of the segments I2 and I3 which are coincident. The shaft 34 has eccentric trunnions 35 and. 36 at opposite ends thereof which carry links 31 and 38 extending along the sides of the body member and of such length as to extend beyond the segment l2. A roller 39 is carried between the links 31' and 38 on a pin 4| which has a knurled head 42 and a threaded end 43, the pin passing through openings 44 and 45 in the links 31 and 38 as shown in Fig. 6, the threaded end 43 of the pin engaging threads in the opening 45. The pin 4i and roller 39 are positioned to leave a space between the segment l2 and the roller for the reception of a follow-bar 46 presently to be described more in detail. The links 31 and 38 also have openings 41 and 48 similar to the openings 44 and 45 for reception of the pin 4| in the manner shown in Fig. 8 so as to receive a follow-bar 49 between the roller and the segment l3. The trunnion 35 extends beyond the link 31' and is squared as shown at ii to receive a lever 52 which functions through manual rotation to adjust the relative positions of the pin and the links 31 and 38 and to thereby varyv within limits the distance between the roller 39 and thesegments l2 or l3 as the case may be. a.

A follow-bar, shown .in Fig. 3, has atopposite ends the head portions 46 and 49 adapted for cooperation with the segments 12 and I3, re-

spectively, the head portions being connected by; a bar 53. The head portion 46 has grooves 54 and 55, and the head portion 49 has grooves 53.; and 51 of a curvature corresponding to the out-' side radius of standard pipe sizes and correspond.- v

ing to the curvature of the grooves I8, l9, 2| and 22 of the segments l2 and 13, the depth of the grooves being such that the follow-bar grooves in combination with the segment grooves substantially completely enclose the pipe as shown in Figs. 7 and 8. The head portions 46 and 49 have a length substantially equal to the distance from the abutment members 23 and 29 to the trailing end of the segments l2 and I3, respectively, so as to roll along the full length of the segments during the bending of a tube. It will be noted from Figs. 6 to 8, inclusive, that the width of the follow-bar head portions is somewhat less than the width of the segments [2 and I3, and while this is not necessarily true, this construction is adopted to keep the weight and size of the follow-bar to a minimum. The followbar thus will shift from side to side depending upon the size of tube being bent.

To bend a tube utilizing this bending device, the tube is inserted under one of the abutments conforming to the tube size as shown in Fig. 4 in which a tube of /1" outside diameter is inserted under the abutment 24. The follow-bar is then inserted between the tube and the roller 39 with the groove 55 thereof seated over the tube and the tube resting in the groove I8 at the leading end thereof, the end of the followbar substantially abutting against the abutment member 23 in the position shown in Figs. 4 and 6. Preferably during this operation the lever 52 is swung to the position shown in Figs. 4 and 6 to allow of a maximum amount of space between the roller 39 and the segment I2. When the tube and follow-bar have been positioned, the lever 52 is rotated to the position shown in Figs. 5 and 7 so as to draw the roller toward the segment l2 and pull the follow-bar up until it approaches contact with the segment l2. The handle l4 and the free end of the follow-bar are then grasped by the operator as shown in Figure 1 and moved toward each other. As a result, the follow-bar is pressed against the segment I! in the manner shown in Figs. 5 and 7 slightly ahead of the longitudinal center line through the links 31 and 38, compressing the tube in this area and at the same time bending the tube in the same area. As the follow-bar moves along the segment I2, the roller 39 simultaneously moves along so as to maintain the point of maximum pressure slightly ahead of the roller and in the bending area. The lever 52 should be adjusted so that this condition prevails; in other words, so that the roller is as close to the fulcrum of the followbar as possible and yet is not directly on the fulcrum. The closer the roller comes to this condition the more difficult it will be to roll the follow-bar along the segment, but in general the more perfect will be the bending result. Through this close adjustment of the point of bending and the application of forming pressure which serves to confine the walls of the tube within the area in which the bending occurs, flattening, crimping or rippling of the tube is prevented even in thin walled and soft metal tubes. For the bending of smaller tubes the handle 14 is screwed into the socket II, the roller 39 is moved to the holes 41 and 48, and the bending operations are carried out in like manner against the segment l3 as shown in Fig. 8 employing the opposite end of the follow-bar with the head 49 cooperating with the segment l3 and the head'48 being used as the grip or handle for the purpose of rotating the follow-bar.

It will be seen that we have provided a light weight, small and eflicient bending device for hand operation. By employing two oppositely spaced segments on the same body member, each of which have two grooves in parallel planes, we are enabled to bend four different sizes of tubes and yet maintain the body light in weight and comparatively thin. This structure of the device is of merit in any manually operated tube bending mechanism. On the other hand, in the provision of a follow-bar of the character described and the utilization of a roller and shoe cooperating therewith in the manner set forth, we are enabled to bend thin walled and soft metal tubes with an ease and convenience heretofore unknown. Through this arrangement we are enabled to provide .a bender for thin walled tubes of such simplicity and efficiency that the tool may be carried about on the work by the workman in the same manner as any other tool and through which perfect bends may be formed in such tubes. An important part of the invention is the eccentric mounting of the links 31 and 38 which permits of adjustment of the position of the roller so as to predetermine the length of the work arm on the lever.

While we have thus described and illustrated a specific embodiment of the invention by way of illustration, we are aware that the principles thereof may be incorporated in specifically different embodiments, and we do not wish to be limited except as required by the prior art and the scope of the appended claims, in which we claim:

1. The combination in a tube bender of a body member having a handle for supporting the bender in the hand of the operator and an arcuate bending segment fixed thereon provided with an annular groove for receiving a tube, a round roller carried on said body member in spaced relation to the periphery of said segment and adapted to move therealong in concentric relationship, a follow-bar having a handle portion and a head portion shaped for reception between the roller and the segment in tangential relation to the segment, said head portion having a groove for registration with the groove in the segment to receive a tube therebetween and shaped to abut against the segment upon compression of the tube, said head portion having an outer surface for movement of the roller thereover in response to movement of the follow-bar to compress and bend the tube in a shifting area of contact forwardly of the roller between the bar and the segment as the handles are moved together.

2. The combination recited in claim 1 wherein means are provided for adjusting the radial position of the roller.

3. The combination in a hand operated tube bender of a body member having a handle for supporting the bender in the hand of the operator and an arcuate bending segment provided with an annular groove for receiving a tube, links journaled on opposite sides of said body member at the center of curvature thereof and projecting beyond said segment, a roller pivotally carried between said links in spaced relation to said segment, a follow-bar having a head portion including a flat outer side and an inner side provided with longitudinal grooves for the reception of that portion of the tube projecting from the groove in said segment and having a relatively long handle adapted to act as a lever, said head portion being shaped for reception between the roller and the segment in tangential relation to the segment, said roller serving as a fulcrum for compression of the tube upon movement 011 the handle on said follow-bar to move over the outer side of the follow-bar with movement of the latter to move the point of contact progressively along the segment forwardly of the roller and bend the tube without relative sliding movement of the segmental follow-bar against the tube, and eccentric means for moving the point of support of said links to vary the distance between the segment and the roller.

4. The combination recited in claim 3 wherein said eccentric means includes a pin positioned in said body substantially at the center 01' curvature of said segment having eccentric trunnions at its ends for reception of said links, and means for rotating said pin to move. the trunnions and thereby vary the distance between the roller and the segments in any position of the roller.

JOHN H. ABRAMSON. EDWIN C. SWANSON. 

